Caption: Gene therapy. Conceptual computer artwork representing gene therapy, showing beams of DNA (deoxyribonucleic acid, spiral structures) being targeted at a patient. This involves new genes being used to replace defective ones. The first approved gene therapy took place in 1990. Since then, a variety of methods and diseases have been investigated and several pioneering treatments attempted. The usual method is viral delivery, where viruses are used to insert new genes into the patient's genome. The areas targeted in this picture include the brain, heart, lungs, pancreas and colon. Disorders in these areas studied in gene therapies include Parkinson's disease, coronary heart disease, cystic fibrosis, diabetes and colon cancer.